(a) Field of the Invention
The invention relates to a liquid crystal display and a manufacturing method thereof.
(b) Description of the Related Art
Among display panels, a liquid crystal display (“LCD”) is one of flat panel displays that is being widely used, and includes two display panels in which field generating electrodes such as a pixel electrode and a common electrode, etc., are formed, and a liquid crystal (“LC”) layer disposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer that determines the orientations of LC molecules therein to adjust polarization of incident light.
Among the liquid crystal displays, the liquid crystal display that is mostly used is a structure in which field generating electrodes are provided in two display panels. Among them, the mainstream structure is a structure in which a plurality of thin film transistors and pixel electrodes are arranged in a matrix form in the display panel (hereinafter referred to as “thin film transistor array panel”), and color filters of red, green, and blue are formed and a common electrode covers the entire surface thereof in the other display panel (hereinafter referred to as “common electrode panel”).
However, when the pixel electrodes and the color filters are formed on the different display panels, it is difficult to correctly align the pixel electrodes and the color filters such that an alignment error may be generated. To solve this problem, a color filter on array (“COA”) structure in which the pixel electrodes and the color filters are formed on the same display panel is provided.
Also, when considering a combination margin when combining the thin film transistor array panel and the common electrode panel, a light blocking member such as a black matrix is formed with a larger size than a predetermined size. However, the aperture ratio may be decreased by the size of the black matrix such that the black matrix may be formed in the thin film transistor array panel.
An interval of the liquid crystal layer between two display panels is referred to as a cell gap, and the cell gap influences general operation characteristics of the liquid crystal display such as response speed, contrast ratio, viewing angle, and luminance uniformity. If the cell gap is not uniform, a uniform image is not displayed on the whole screen such that the display quality is deteriorated. Accordingly, to maintain the uniform cell gap throughout the whole region of the substrate, a plurality of spacers is formed on one of the two panels.
Particularly, the spacers and the light blocking member may be simultaneously formed to simplify the process. However, if the spacers (column spacers) and the light blocking member are simultaneously formed, a reflow is generated in a post-hardening process among the manufacturing process.
As described above, if the reflow is generated in the spacer manufacturing process, a taper of the spacer is deteriorated such that a process margin becomes poor, and a compression characteristic of the spacer to maintain the cell gap is deteriorated by an external impact.